Ara-AC, a drug synthesized in this laboratory, is about to begin Phase I clinical trials in three institutions. A patent application describing the antiviral activity of 4- deaminocytidine (zebularine) was filed. A hexamethylene bis-hydantion, which was 10 times more potent than HMBA in differentiating HL-60 cells, was the subject of a patent application. Cyclopentenyl cytosine (CPE-C) has excellent preclinical antitumor activity as well as potent activity against both DNA and RNA viruses. A patent application was filed on this potential clinical antitumor candidate.